<!DOCTYPE html>
<html lang="zh-CN">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>

    body{

      background-color: #000;
    }

    .heart {
      width: 400px;
      position: relative;
      height: 400px;
      margin: 150px auto;
      animation: heartGo .5s infinite alternate;
    }

    @keyframes heartGo {
      from {}
      to {
        transform: scale(1.2);
      }
    }

    .heart div{

      width: 200px;
      height: 200px;
      background-color: #f00;
      position: absolute;
      box-shadow: 0 0 20px red;
    }

    .left,.right{
      border-radius: 50%;
    }

    .right{
      right:60px;
    }

    .heart .bottom{
      width: 193px;
      left:76px;
      bottom:127px;
      transform: rotate(45deg);
    }

  </style>
</head>
<body>
  <div class="heart">
    <div class="left"></div>
    <div class="right"></div>
    <div class="bottom"></div>
  </div>
</body>
</html>